Costco Copycat Chocolate Cake Recipe

Ingredients

For Cake:

  • 2 cups all purpose flour, spooned and leveled, not packed

  • 2 cups sugar

  • ¾ cup dutch processed cocoa

  • 2 tsp baking soda

  • 1 tsp baking powder

  • 1 tsp sea salt

  • ½ cup sour cream, or greek yogurt

  • ½ cup vegetable oil

  • 4 oz dark chocolate, high quality

  • 3 eggs, large

  • 2 tsp vanilla extract

  • 1 cup buttermilk

  • 1 cup hot water, or brewed coffee for more enhanced chocolate flavor

For Frosting:

  • 1½ cups unsalted butter

  • 8 oz cream cheese, room temp

  • 1 tbsp vanilla extract

  • 6 oz powdered sugar, sifted

  • 1½ cup dutch processed cocoa, sifted

  • ¼ cup heavy whipping cream

  • ½ tsp salt

For Ganache (optional):

  • 1 cup dark chocolate chips

  • ¾ cup heavy whipping cream

Instructions

Cake:

  1. Preheat oven to 350 degrees F.

  2. In a large bowl or stand mixer, whisk together the dry ingredients - flour, sugar, cocoa, baking soda, baking powder, salt, and powdered buttermilk if using the powdered form.

  3. Melt the chocolate in 20 to 30 second bursts in the microwave. It's done when the chocolate is almost completely melted, but not all the way. Stir together until all of it is melted and smooth. Set aside to cool down.

  4. Whisk together the wet ingredients (sour cream, oil, eggs, vanilla, buttermilk, hot water, and melted chocolate) in a separate bowl. Then combine with the dry ingredients.

  5. Mix together well until combined. Just don't over mix as that can lead to a crumbly cake.

  6. Pour into 3 8-inch greased cake pans, 2 9-inch pans, or 24 cupcake liners.

  7. Bake for 22 to 26 minutes. The cake is done when the toothpick comes out with moist crumbs on it. Transfer to cooling racks when done.

Frosting:

  1. Beat the butter and cream cheese for about 2 minutes.

  2. Slowly add the sifted powdered sugar and cocoa powder intermittently with the heavy whipping cream. Add the vanilla and salt. Add more cream as needed to get a soft consistency.

  3. Beat the frosting for about 2 to 3 minutes.

Ganache (optional):

  1. Heat up the heavy whipping cream in the microwave for about 30 to 45 seconds till hot. Pour over the chocolate chips. Cover and rest for a couple minutes to let it begin to melt the chocolate.

  2. Whisk together the chips and ganache until smooth. Pour it into a drip bottle or use a spoon to add a drip to the cake.

  3. If the ganache is too runny, let it cool longer. If it's still runnier than desired, add additional melted chocolate. If it's thicker than desired, add a little more warm heavy cream and whisk together.

To Assemble:

  1. Trim cake layers if needed to help achieve nice even layers.

  2. Spread a small amount of frosting on a cake board, then place the first cake layer down.

  3. Add an even layer of frosting, top with a cake, layer, add the layer of frosting, then add the last cake layer.

  4. Apply an even, thin layer of frosting around the entire cake. Leave as is if frosting a semi-naked cake. Otherwise, place the cake in the freezer for about 15 minutes to create the "crumb coat".

  5. Spread remaining frosting around the cake and garnish, drizzle ganache if desired, and pipe as desired.